Finding the Third Proportional to 2,138.91 and 3,211.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,138.91 : 3,211.31 = 3,211.31 : x
2. Step 2: Convert to fraction form
   2,138.91/3,211.31 = 3,211.31/x
3. Step 3: Cross multiply
   2,138.91x = 3,211.31 × 3,211.31
4. Step 4: Simplify right side
   2,138.91x = 10,312,527.97
5. Step 5: Solve for x
   x = 10,312,527.97/2,138.91
6. Step 6: Final answer
   x = 4,821.40